On the Fourth of July, the sky above towns across the nation will glow in a blitz of factory-made colors.

But some of the biggest, best and most innovative fireworks won’t be on display during the holiday. Instead, they’ll be tucked away in the garages and home workshops of hobbyists like Tom Niesen.

“I’m an old-school firework artist,” said Niesen, a 43-year-old electrical technician in Duluth, Minnesota. “I build some of the largest fireworks in the nation. It’s something very few people can do.”

The fact that people say, ‘That’ll never work,’ does not stop the hobbyist.

Essentially all public shows will use mass-produced factory fireworks, mostly from China; competition and regulation have largely snuffed out U.S. makers. These fireworks are cheap and abundant, great for post-barbecue reverie but unsatisfying to discerning eyes.

“In municipal displays you’ll see quantity over quality,” said Niesen, a member of Northern Lighter Pyrotechnics. “For something really spectacular, the public should come to the conventions of fireworks clubs.”

Amateur clubs are the source of many of the improvements in firework technology, said John Conkling, a chemist at Washington College in Maryland and author of The Chemistry of Pyrotechnics. Clubs like the Northern Lighters attract licensed hobbyists with the diligence and dedication to innovate.

“The fact that people say, ‘That’ll never work,’ does not stop the hobbyist,” Conkling said.

Innovations have traditionally come slow to the field: Basic firework chemistry hasn’t changed much in the past 200 years. One thing that could really use some help from ambitious hobbyists is the lackluster blue we’re forced to put up with, Conkling said. The copper compounds that give fireworks a blue color break down under the high heat needed for bright colors.

“So we can get a really bright red, a really bright white, but we’re stuck with a sort of mediocre blue for our national colors,” Conkling said. “There are a lot of amateur pyrotechnicians pursuing this. They’ll spend their winter nights in the basement trying to make a better blue.”

Niesen has been working all year on four firework shells: each a 50-pound cylinder standing 36 inches high and 8 inches across. With these munitions Niesen hopes to take first place in the large-shell category at the annual Pyrotechnics Guild International competition in Fargo, North Dakota, in August. He spends up to 50 hours assembling a single firework and has won the last three years he has competed.

“It’s very much chemistry, it’s very much art, and it’s very much skill,” he said. “I make all of my fireworks completely from scratch, starting with the gunpowder.”

Each shell contains three separate fireworks. After launch they’ll send out red, green and blue stars with strobing effects and finish with a “heavy report,” or a big, grand boom.

As a matter of pride, the salts and metals inside the shells are hand-mixed, the shells tied up with string and paper with no glue or plastic in sight. Niesen builds fireworks in the traditional Italian way, using techniques that date from the 1700s.

“I’ve been playing with fireworks all my life,” he said. “At about 19, I was introduced to a club that builds and shoots fireworks, and it was an awakening to me. I’ve always been an artist, and I never found satisfaction in my work. It’s my fireworks that allow me creative expression.”